title: Molecular Characterization of the Multiple Interactions of SpsD, a Surface Protein from Staphylococcus pseudintermedius, with Host Extracellular Matrix Proteins.
abstract: Staphylococcus pseudintermedius, a commensal and pathogen of dogs and occasionally of humans, expresses surface proteins potentially involved in host colonization and pathogenesis. Here, we describe the cloning and characterization of SpsD, a surface protein of S. pseudintermedius reported as interacting with extracellular matrix proteins and corneocytes. A ligand screen and Western immunoblotting revealed that the N-terminal A domain of SpsD bound fibrinogen, fibronectin, elastin and cytokeratin 10. SpsD also interfered with thrombin-induced fibrinogen coagulation and blocked ADP-induced platelet aggregation. The binding site for SpsD was mapped to residues 395-411 in the fibrinogen γ-chain, while binding sites in fibronectin were localized to the N- and C-terminal regions. SpsD also bound to glycine- and serine-rich omega loops within the C-terminal tail region of cytokeratin 10. Ligand binding studies using SpsD variants lacking the C-terminal segment or containing an amino-acid substitution in the putative ligand binding site provided insights into interaction mechanism of SpsD with the different ligands. Together these data demonstrate the multi-ligand binding properties of SpsD and illustrate some interesting differences in the variety of ligands bound by SpsD and related proteins from S. aureus.
authors.affiliation: Department of Molecular Medicine, Institute of Biochemistry, Pavia, Italy.
authors.forename: Giampiero
authors.initials: G
authors.lastname: Pietrocola
authors.forename: Joan A
authors.initials: JA
authors.lastname: Geoghegan
authors.forename: Simonetta
authors.initials: S
authors.lastname: Rindi
authors.forename: Antonella
authors.initials: A
authors.lastname: Di Poto
authors.forename: Antonino
authors.initials: A
authors.lastname: Missineo
authors.forename: Valerio
authors.initials: V
authors.lastname: Consalvi
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Foster
authors.forename: Pietro
authors.initials: P
authors.lastname: Speziale
mesh_terms: D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D004285:Dogs; D004549:Elastin / Q000737:chemistry / Q000378:metabolism; D016326:Extracellular Matrix Proteins / Q000737:chemistry / Q000378:metabolism*; D005340:Fibrinogen / Q000737:chemistry / Q000378:metabolism; D005353:Fibronectins / Q000737:chemistry / Q000378:metabolism; D054884:Host-Pathogen Interactions / Q000235:genetics*; D006801:Humans; D053550:Keratin-10 / Q000737:chemistry / Q000378:metabolism; D008024:Ligands; D016297:Mutagenesis, Site-Directed; D011485:Protein Binding; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000302:isolation & purification; D013210:Staphylococcus / Q000378:metabolism*
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D016326:Extracellular Matrix Proteins; D005353:Fibronectins; D008024:Ligands; D011994:Recombinant Proteins; C027539:fibrinopeptides gamma; D053550:Keratin-10; D005340:Fibrinogen; D004549:Elastin